Ice cream fork. Wmpearl / wikimedia / 2011 / Public Domain
Ice cream forks have a flattened bowl reminiscent of a spoon, but with tines cut into the tip of the spoon. With the handle, they will be about 12 to 15 cm (5 to 6 inches) long.
They are for eating with, not serving.
They make it easier to eat cake and ice cream, ice cream cakes, other frozen or semi-frozen desserts, etc, and can dig easily into hard, frozen ice-cream.